The present invention relates to an image reading method and apparatus for reading an original image of, e.g., a developed photographic film, and a storage medium.
In a film scanner as an image reading apparatus, conventionally, a film original (transparent original) such as a microfilm or a photographic film is irradiated by an illumination optical system from the back. The transmitted light is projected to an imaging plane of a photoelectric conversion element through a projection optical system to form an image transmitted by the light onto the imaging plane. The image is photoelectrically converted by the photoelectric conversion element so that the image information of the film original is electrically converted and output.
In such an image reading apparatus, however, anomalies such as flaws or dust particles sticking to the illumination optical system or the projection optical system appear as black spots on the read image data, resulting in degradation in the image.
The present invention has been made to solve the above problem, and has as its object to provide an image reading apparatus capable of satisfactorily correcting anomalies such as dust particles or flaws to obtain a higher-quality image.
According to the present invention, the foregoing object is attained by providing an image reading apparatus, comprising; light-emitting means for irradiating an original with invisible light and visible light; photodetection means for detecting light from the original irradiated by the light-emitting means to output image data; region detection means for detecting a first image region recognized as anomaly in first image data output by said photodetection means when the original is irradiated with the invisible light from said light-emitting means, and detecting a second image region recognized as anomaly in second image data output by said photodetection means when the original is irradiated with the visible light from said light-emitting means; shift correction means for correcting a shift between the first image region and the second image region; determination means for determining, as an anomalous region on the original, a region in the second image data, which corresponds to the first image region corrected by the shift correction means; and, anomaly correction means for correcting image data in the anomalous region determined by the determination means.
According to another aspect of the present invention, the foregoing object is attained by providing an image reading apparatus, comprising: light-emitting means for irradiating an original with invisible light and visible light; photodetection means for detecting light from the original irradiated by the light-emitting means to output image data; region detection means for detecting a first image region recognized as anomaly in first image data output by said photodetection means when the original is irradiated with the invisible light from said light-emitting means, and detecting an anomalous region corresponding to the first image region in second image data output by said photodetection means when the original is irradiated with the visible light from said light-emitting means; and anomaly correction means for correcting the second image data by amplifying pixel values in the anomalous region detected by said region detection means.
In still another aspect of the present invention, the foregoing object is attained by providing an image reading apparatus, comprising: light-emitting means for irradiating an original with invisible light and visible light; photodetection means for detecting light from the original irradiated by the light-emitting means to output image data; region detection means for detecting a first image region recognized as anomaly in first image data output by said photodetection means when the original is irradiated with the invisible light from said light-emitting means, and detecting an anomalous region corresponding to the first image region in second image data output by said photodetection means when the original is irradiated with the visible light from said light-emitting means, a region corresponding to the first image region as an anomalous region; and anomaly correction means for grouping peripheral region of the anomalous region detected by the region detection means in accordance with pixel values and correcting pixels in the anomalous region, which are sandwiched by pixels of a first group of the peripheral region, to pixel values in the first group.
In still another aspect of the present invention, the foregoing object is attained by providing an image reading method, comprising: an irradiation step of irradiating an original with invisible light and visible light from light-emitting means; a photodetection step of detecting light from the original irradiated in the irradiation step to output image data; a region detection step of detecting a first image region recognized as anomaly in first image data output in the photodetection step when the original is irradiated with the invisible light in the irradiation step, and detecting a second image region recognized as anomaly in second image data output in the photodetection step when the original is irradiated with the visible light in the irradiation step; a shift correction step of correcting a shift between the first image region and the second image region; a determination step of determining, as an anomalous region on the original, a region in the second image data, which corresponds to the first image region corrected in the shift correction step; and an anomaly correction step of correcting image data in the anomalous region determined in the determination step.
In still another aspect of the present invention, the foregoing object is attained by providing an image reading method, comprising: an irradiation step of irradiating an original with invisible light and visible light from light-emitting means; a photodetection step of detecting light from the original irradiated in the irradiation step to output image data; a region detection step of detecting a first image region recognized as anomaly in first image data output in the photodetection step when the original is irradiated with the invisible light in the irradiation step, and detecting an anomalous region corresponding to the first image region in second image data output in the photodetection step when the original is irradiated with the visible light in the irradiation step; and an anomaly correction step of correcting the second image data by amplifying pixel values in the anomalous region detected in the region detection step.
In still another aspect of the present invention, the foregoing object is attained by providing an image reading method, comprising: an irradiation step of irradiating an original with invisible light and visible light from light-emitting means; a photodetection step of detecting light from the original irradiated in the irradiation step to output image data; the region detection step of detecting a first image region recognized as anomaly in first image data output in the photodetection step when the original is irradiated with the invisible light in the irradiation step, and detecting an anomalous region corresponding to the first image region in second image data output in the photodetection step when the original is irradiated with the visible light in the irradiation step; and an anomaly correction step of grouping peripheral region of the anomalous region detected in the region detection step in accordance with pixel values and correcting pixels in the anomalous region, which are sandwiched by pixels of a first group of the peripheral region, to pixel values in the first group.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.